The present invention relates generally to crop harvesting machines and more particularly to a new and improved forage harvester machine.
The well known agricultural practice of forage harvesting consists of cutting either green or mature crop material into discrete particles and conveying them from the field to a storage silo where they undergo an acid fermentation to give them an agreeable flavor and to prevent spoilage. This operation, which is commonly referred to as an ensilage process, converts standing crop in the field to livestock feed, commonly referred to as silage. An essential piece of farm machinery used for producing silage is the forage harvester which is adapted to gather crop material from the field, cut it into small particles and then convey the cut crop material to a temporary storage bin or wagon. Harvesters of this type are either self-propelled or pulled by a tractor. Typically, forage harvesters have a rotary cutter of a generally cylindrical configuration with knives peripherally mounted to cooperate with a fixed shear bar for cutting material as it is passed across the surface of the bar. An optical perforated recutter screen is used under some conditions to reduce the size of the cut crop even further when desirable.
Many forage harvesters are provided with a blower to convey the cut crop to a wagon towed behind or along side the harvester for receiving the crop. In some prior art arrangements, cut crop material is transferred to the blower from the cutterhead by intermediate conveyor means such as an auger system. Single or side-by-side augers are used at right angles or parallel to the axis of the rotary cutter. Problems have been encountered in some instances with this type of mechanism when material accumulates unevenly along the augers and causes clogging. From a design standpoint, augers provide extra moving parts that are subject to wear and thereby reduce overall reliability and serviceability characteristics of the harvester. Furthermore, use of augers increases the power requirements of the harvester especially in crop material having high moisture content.
To overcome problems of this nature some prior art forage harvesters have been designated with cutterhead discharging material directly to the blower without intermediate conveying means. In these direct discharge machines the blower fan rotates about an axis horizontal to the ground. The blower unit receives material fed from the cutterhead directly to the fan blades which in turn convey the cut crop material upwardly through a spout and thence to a bin or wagon. To properly accommodate direct feed type upright blowers the blower spout, the operator's platform or other important components are undesirably offset from the path of travel in prior art self-propelled harvesters. This offset has been necessitated to provide proper clearance for the spout with respect to the many other bulky components of the harvester such as the engine, an operator's platform positioned to permit proper visibility, power transmission mechanisms, a fuel tank of a sufficient size to permit long periods of field operation, etc.